在 2022/4/12 21:29, chenxiaosong (A) 写道:
在 2022/4/12 21:13, chenxiaosong (A) 写道:
On other filesystem, wb error is only cleared when doing fsync() or sync
write(), it should not clear the wb error when doing async write(). Your
patch will clear the wb error when doing async write().
And my patchset mainly fix following problem:
filemap_sample_wb_err() always return 0 if old writeback error
have not been consumed. filemap_check_wb_err() will return the old error
even if there is no new writeback error between filemap_sample_wb_err() and
filemap_check_wb_err().
```c
since = filemap_sample_wb_err() = 0
errseq_sample
if (!(old & ERRSEQ_SEEN)) // nobody see the error
return 0;
nfs_wb_all // no new error
error = filemap_check_wb_err(..., since) != 0 // unexpected error
```
After merging your patchset, NFS will report and clear wb error on
_async_ write(), even there is no new wb error while nfs_wb_all, is this
reasonable?
And more importantly, we can not detect new error by using
filemap_sample_wb_err()/filemap_check_wb_err() while nfs_wb_all(),just
as I described:
```c
since = filemap_sample_wb_err() = 0
errseq_sample
if (!(old & ERRSEQ_SEEN)) // nobody see the error
return 0;
nfs_wb_all // no new error
error = filemap_check_wb_err(..., since) != 0 // unexpected error
```
.
